In fluid systems in various industries, sight glasses are provided to permit visual inspection of the fluid being conveyed through a conduit. The sight glass is positioned within a housing and is secured within the housing by a generally cylindrical, tubular retainer which is threaded within the housing. The retainer only has a relatively small axial end portion which protrudes from the housing. Only this relatively small axial end portion of the retainer may be gripped for installing and removing the retainer. Diametrically opposite recesses are formed within the exposed end portion of the retainer for facilitating its removal.
Conventional methods for removing and tightening sight glasses have employed a screwdriver or a channel locks. However, neither the screwdriver nor the channel locks works satisfactorily. Additionally, such conventional methods often damage the sight glass and/or retainer. In locations having extremely limited access due to obstructions and limited availability of space, it is impossible to use a screwdriver or channel locks to remove or secure the retainer.